1. Field of the Invention
The invention relates to abrading machines and, more particularly, to an abrading machine having an indexing tool carrier for presenting a plurality of tools to the user. In a preferred embodiment according to the invention, the tools comprise endless bands of abrasive material. An illustrative use environment includes sharpening wood chisels. A number of additional features and objects will be apparent in connection with the following discussion of preferred embodiments and examples.
2. Prior Art
Wood chisels are precision instruments, especially carving chisels for fine, exacting work in soft or hard woods. Practiced users of them keep the edges razor sharp. Working with carving chisels is many times easier when the edges are kept razor sharp. Only rough, inaccurate work can be expected from a dull chisel. A dull chisel requires more power to use and may actually be dangerous. Even if stored during non-use to protect their edges, and even if use is limited to wood and none is ever used to pry, the edges will dull after time. At that date proper maintenance of the chisels requires sharpening them.
The known methods for sharpening carving chisels include a wide variety of hand tools as well as grinding wheels. Use of the hand tools is time consuming. A skilled practitioner might take three hours to get a precision edge. The state of the art grinders are typically wet stone grinders. The grinding wheel might be two inches wide (5.1 cm) and ten inches diameter (25.4 cm) and turns in a water trough to spread a water film over it to act as a lubricant for faster beveling while continuously cooling the dull edge to prevent bluing. One manufacturer includes a leather honing wheel alongside the grinding wheel for removing any burr and to hone the edge, i.e., to polish out any small grooves/ridges left in the cutting edge after working it on the grinding wheel.
There are shortcomings with the grinding wheels of the prior art. They produce a hollow-ground edge, i.e., not a flat primary bevel but a concave bevel. And in spite of the water film they easily grind too fast and "blue" the edge, which means that they caused the steel to lose its temper. Abrading machines using grinding wheels often have no more than two different grit wheels, such as coarse and intermediate, making it necessary to use another tool to finish a typical task, eg., to hone the workpiece's work edge. Grinding wheels are prone to uneven wear, require regular maintenance, and are expensive to replace when worn out. What is needed therefore is an improved sharpening apparatus that overcomes the shortcomings of the prior art without sacrificing simplicity and economy.